yes twilite, you do have that fuzzy feeling the first few days lowcarbing. think of sugar as a drug that you are really dependent on. when you low carb, you drastically drop back on the sugar intake. you're going through withdrawal symptoms. you'll feel great in a few days. you'll sleep better at night and you'll have increased energy during the day. just hang in there.
by the way, what "mayo clinic diet" are you doing? the only one that i know of is the one i talked to you about.